Balanced steam-valve



(No Model.)

3 SheetS--Shee'g 1, W. W. LEWIS.

BALANGBD STEAM VALVE.

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(No Model.) 3 Sheets-Sheet 2.

W. W. LEWIS.

BALANGED STEAM VALVE. Ng. 337,688. Patented Mar. 9, 1886.

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7 'I 'l um* Nil (No Model.) 3- Sheets-Sheet 3. W. W. LEWIS. BALANGED STEAM VALVE.

No. 337,688. Patented Mar, 9.118864.

i y 1F50] l l x l x x x UNITED STATES PATENT OFEicEG VILLIAM XV. LEWIS, OF CINCINNATI, OHIO.

BALANCED STEAM-VALVE.

SPECEPICATION forming part of Letters Patent No. 337,688, dated March 9, 1886. Application filed Octolzer 27,1884. Serial No. 146,638. (No model.)

T0 all whom it may concern,.-

Be it known that I, WTLLIAM W. LEWIS, a citizen of the United States, residing at Gincinnati, Ohio, have invented new and useful Improvements in Balanced Steam-Valves, of which the following is a specification.

My invention relates to steam engines, having more particular reference to improvements in the construction and arrangement of balanced slide valves, which improvements, though applicable to all slide-valve engines, are more especially useful in locomotives operating on railways and road or traction7 engines.

These consist, rst, in the construction and arrangement of a balancing plate and piston, in connection with the valve-chest and its cover, for relieving the steam-pressure upon the valve; secondly, in a valve having a recessed back, in combination with the balancing-plate and a hollow piston-rod, forming at the same time a vacuum chamber and oilfeeding reservoir; thirdly, in the provision and arrangement of an external spring in connection with and acting upon the balancingplate; fourthly, in the construction of the piston; fthly, in the construction of the jointconnection between the balancing-plate and its supporting piston-rod; sixthly, in the provision and arrangement of oil-channels in the steam-chest cover, balancing-plate, and valve adapted to secure perfect lubrication of the valve upon its seat and against the balancingplate.

Mechanism embodying my invention is illustrated in the accompanying drawings,

in Which Figure l is a longitudinal sectional elevation of the valve-chest and auxiliary cylinder, showing the balancing-plate, valve, balancing piston, and spring in position, and indicating the construction and relation of the parts; Fig. 2, a plan of the valvechest with one half of the cover removed and the remaining half of the cover sectioned through the auxiliary cylinder on the plane x x of Fig. l; Fig. 3, a front elevation of the valve chest and auxiliary cylinder, one half being sectioned in a central vertical plan; Fig. 4, a plan View of the valve-chest and auxiliary cylinder, one-half of the cover of the latter being removed and the auxiliary cylinder sectioned above the piston. Fig. 5 shows a Weighing apparatus, as hereinafter explained, Figs. G and 7, a longitudinal sectional elevation (side) and a plan of a niodified form of valve construction.

Referring to the drawings, in which the parts designated are indicated by letters of reference, A is the auxiliary cylinder, cast upon the valve-chest' cover J; B, the piston operating therein; a, the piston-rod projecting downward into the valve-chest and carrying at its lower end a plate, I), resting in sliding contact upon the valve D; k, the actuatingrod of the slide-valve, and k the yoke securing the rod k to the valve D; E E, the inletports for admission of steam to the valvechest, and F G the receiving and exhaust ports, respectively, in the valve-seat, communicating with the cylinder. y

The general arrangement of the auxiliary cylinder upon the valve-chest cover and the piston with rod supporting a plate within the valve-chest in sliding contact with the valve is the same as in other structures of this nature, except in so far as modified by my improvements, as set forth in the following description. Instead, however, of leaving the lower end of the auxiliary cylinder entirely open into the valve-chest, I. construct the valve-chest cover as a substantially continu-Y ous plate with openings b b, constituting steampassages connecting the interior of the auxiliary cylinder with that of the valve-chest, and a central opening through a thickened boss, b', for the passage of the piston-rod a. This construction not only secures uniformity in the expansion and contraction of the cover and cylinder parts, but furnishes a guidebearing for the piston near the balancingplate, which enables it to more perfectly support and retain the latter in position against the lateral strains of friction.

The auxiliary piston-rod is preferably constructed of steel turned to different dimensions at different portions of its length, as shown in Fig. l, is hollow throughout its 1ength,`and extends upward through the auxiliary cylinder, and through an arch-piece, h, formed upon the cover H of the auxiliary cylinder. The hollow cavity through the rod a opens into a depression, d, in the upper side IOO f ure upon the piston B, in order to relieve the valve as much as possible, (as the sudden and irregular movements of the engine in traversing rough roads are likely to lift the plate at times from the valve,) I arrange a coiled spring surrounding the piston-rod a above the cylinder A and within the arch-piece It', bearing against an adjustable nut, e', upon the pistonrod. The action of thespring assists the weight of the balancing piston and plate, and being unaffected by the jolting of the engine, as is the weight ofthe parts, tends to preserve constant contact between the valve and its balancingplate. The bearing-surface of the nut e and its seat are so fitted as to allow a slight variation from a rigid right-angled position of the piston-rod and balance-plate, the joint being a species of ball-joint, and the foot of piston-rod and its seat are likewise treated. The

'piston B of the auxiliary cylinder is held against the shoulder on the hollowpiston-rod a by a nut, h, Fig. 1, and over this is slipped a follower, S, perforated, as shown in plan section, Fig. 4. The latter serves, in connection with the bottom plate of the piston-head B, to clamp the packing material in the outer edge of the piston against an adjustable annular rim, c. circumference of the latter, threaded in an upwardly-projecting annular lug on the piston-head. Vertical screws hold the follower to the annular lug, and by .means of the perforations the adjusting-screws t' are accessible for purposes of enlarging the packing or otherwise. These may be placed at as many and convenient intervals as thought necessaryto secure proper and even adjustment. The construction of t-he auxiliary cylinder' gives easy access to its interior,whether the engine be in =operation or at a stand. The simple form of the slide-valve allowslthe exhaust-cavity to be extended in length and the height of the same reduced, whereby -a gain is secured in cost fromthe consequent reduction in the height of the steam-chest.

The countersunk chamber in the back of the valve being lled with oil, therebypreventing access of air or steam, serves practi` cally as a vacuum-chamber, maintaining a close vunion between the balancing-plate and the valve, enabling me to increase they upward' lift7 of the plate, so as to act similarlyupon the valve and counteract its weight, or, even by means of. suitable weighing apparatus, to determine such weight or downward pressure when understrain. The oil likewise assists, incidentally, in the proper lubrication of ythe Radial screws i ,bear on the innerv moving faces, and through the mediumof oilholes in the valve the face and seat of the valve are-likewise lubricated. l A. circular oil-chamber, O,within the steam-chest cover gives additional means of lubrication, and with the oilholes through the balance-plate allows more Y perfect lubrication of the valve-seat.

I have shown in Fig. 5 an ordinary scale-V beam with weights, adapted at one end for' ,f

.connection with the projecting hollow piston:

rod a, and at the other for the attachment of suitable weights, the fulcru m being between. By means of this apparatus the actual equilib- .rium maintained at different parts of the Y stroke may be measured, the force necessary to raise the valve and balance -plate being made apparent bythe amount of weight on'- thescale-beam, whereby the engine-builder Imay be the better guided in proportioning the parts of the valve. Figs. 6 and 7 show a modified form of construction. I pass the hollow piston-rod vt through astufng-box in the steam-chest cover containing a gland, allowing proper packing to be done, as ordinarily, and attach the other Y end to a steel or other elastic tension-plate, G, supported by the studs I (two or more) upon the cover. These are adjustable in their seats,

and by them the proper adjustment of the tension plate may be eii'ected to secure the most complete balance of the valve. before, the weighing method may be employed to determine the equilibrium maintained by the balance-plate and valve. In the latter IOO modification the balance is performedby a tension-plate instead of the steam, and it will n be evident that, as in the otherform, a rigid arch might be constructed on the valve-chest cover and suitable elastic spring or springs introduced instead of a tension-plate, or that more than one tension-plate might be used. I consider these variations as a part of my improvement.

I am aware that balanced valves are not new; that they have before this been constructed with an auxiliarycylinder upon the steam-chest cover containing a balancing-piston and carrying a balancing-plate bearing upon the slide-valve, wherein a spring surrounding the piston-rod above the' balancingpiston furnishes the slight excess of downward force required to keep the valve seated. I do not, therefore, broadly claim such construction. l

I claim and desire to secure by Letters Patent of the United StatesllO sliding steam-tight connection with the back of the valve, a central rod supporting the balance-plate and extending through a close-it ting orifice in the steam-chest cover for guid ing said rod vertically and resisting the side strains caused by the friction of the valve and plate, and means, substantially as described, for balancing the plate from the outside of the steam-chest cover, substantially as set forth.

3. In a steam-engine, the combination of an auxiliary cylinder formed upon the outside of the steam-chest cover, a piston fitted therein, a piston-rod extending thence through a closeiitting orifice of the cover into the steam-chest and supporting a balance-plate upon the back of the valve by a ball-joint connection, said steam-chest cover being also perforated for the admission of steam into the cylinder from the chest, substantially as specified.

4. In a steam-engine, the combination of a slide-valve with a recessed back, an auxiliary cylinder upon the steam-chest cover, the latter perforated for the admission of steam from the chest into the said cylinder, a piston in said cylinder carrying a holloWpiston-rod eX- tending entirely through said cylinder from the outside and passing through a close-fitting orifice in thesteamchest cover, andabalanceplate supported ou said piston-rod by a ball- 3o joint connection, arranged and operating substantially as and for the purpose set forth.

5. In asteam-engine employing aslide-valve and actuating mechanism, a balance steam-cylinder upon the steam-chest cover and embodied therewith, containing a piston,and central depending piston-rod passing through a bossed orifice in the steam-chest cover, the latter being perforated to allow free passage of steam into the balance-cylinder, the object of the boss being to furnish rigid support against the lateral strains of friction, substantially as described.

6. In balanced-valve mechanism of the kind described, the combination of an auxiliary cylinder formed upon the steam-chest cover, communicating with the steam-chest interior, as described, the piston therein constructed as described, the hollow piston-rod and its jointure to the balance-plate by ball-bearing, as described, the bossed orifice in the steamchest cover, and the rigid arch at the top of the auxiliary cylinder, With contained coiled spring surrounding the piston-rod, arranged and operating as described.

7. In a steam-engine, the combination of a slide-valve, a balance-plate resting on the upper face of the same, an auxiliary cylinder upon the steam-chest cover, a piston itted therein, a piston-rod supporting the balanceplate and secured to said piston,said rod extending outwardly above said cylinder, and a spring secured to and acting upon said rod to assist in preserving contact between the balanceplate and valve, substantially as set forth.

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses.

VILLIAM XV. LEWIS.

Vitnesses:

L. M. HosEA, R. M. HosEA. 

